The Group 3A/ Group 5A semiconductors are composed of equal amounts of atoms from Group 3A and Group 5A— for example, InP and GaAs. These types of semi-conductors are used in light-emitting diodes and solid-state lasers. What would you add to make a p-type semi-conductor from pure GaAs? How would you dope pure GaAs to make an n-type semiconductor?